With reference to FIG. 38 to FIG. 40, a skin body 201 disclosed in paragraph 0030 and paragraph 0043 and FIG. 4 of PTL 1 is described. As depicted in FIG. 40, in the skin body 201, notch parts 203 are formed at side edge parts of the skin body 201 to form folding parts 202, and the side edge parts between adjacent notch parts 203 are folded along folding lines 204 indicated by dotted lines to form the folding parts 202. To prevent the folded folding parts 202 from spreading, as depicted in FIG. 38 and FIG. 39, the adjacent folding parts 202 are fixed together with support members 205.
Also, as depicted in FIG. 38 and FIG. 39, when the plurality of skin bodies 201 are attached to a ball main body 206 configured as a sphere, the folding parts 202 of the adjacent skin bodies 201 are bonded together with a bonding agent, the support members 205 are bonded to the ball main body 206 with a bonding agent, and cavity parts 207 are formed between the skin bodies 201 and the ball main body 206.
However, in the skin body 201 disclosed in PTL 1, with the folding parts 202 bonded by a bonding agent to the support members 205 which are members separate from the skin body 201, the folded shapes of the folding parts 202 are kept, thereby making a complex structure.